SAR11 and related ribosomal RNA genes exist in nearly every pelagic marine bacterioplankton community but the cultivation of the microorganisms that carry these genes have failed in the past. In August 8 Nature, Michael Rappe and colleagues at Oregon State University, US, report the first successful cultivation of the ubiquitous SAR11 marine bacterioplankton clade (Nature 2002, 418:630-633).Rappe et al. inoculated fresh Oregon coast seawater samples into microtitre dish wells by dilution, such t